Revivifying fuller&#39;s earth



. E: WHLSON Filed May 19, 1924,

REVIVIFYING FULLEHS- EARTH Patented Dec. 23, 3024.

ROBERT E. WILSON, OF CHICAGO, ILLINOIS, ASSIGNOR T0 STANDARD OIL COMPANY, OF

WHITING, INDIANA, A CORPORATION OF INDIANA.

REVIVIFYDTG FULLERS EARTH.

Application filed May ISL 1924. Serial No. 714,816.

To all whom it may concern:

Be it known that I, ROBERT E. WILSON, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Revivifying Fullers Earth, of which the following is a specification.

The present invention relates. to improvements in revivifying fullers earth, and will be fully understood from the following description, illustrated by the accompanying drawings in which: 7

Figure 1 shows in side elevation, and somewhat diagrammatically, apparatus suitable for carrying the present invention into efi'ect, and

Fig. 2 is a cross sectional View through. the furnace shown in Fig. 1.

In carrying the resent invention into effect, the spent ful ers earth, used, for example, in decolorizing petroleum oil distillates or residue oils, and washed with naphtha to remove excess of oil, is charged into a suitable furnace 5, which may be, for example, a vertical cylindrical furnace mounted in a setting 6 of suitable insulating material.

In the bottom of the setting, a grate or other suitable means for firin the furnace is provided. The bottom 9 o the furnace, which may be perforated, may suitably be sloped to one side, to permit a free discharge of the revivified fullers earth through the chute 10. Suitable means are provided for carrying away combustion gases from the furnace; for example, the furnace may be surmounted by a dome 11 provided with a flue 12 leading to a stack 13, the lower portion only of which is shown.

In carrying out the present invention, the spent and washed fulle'rs earth to be revivified is charged into the furnace to a level somewhat below the tops of the pipes 14. The furnace is then fired until the fullers earth in the bottom of the furnace directly above the grate or other firing means is heated to a temperature at which combustion will begin on access of air, say above 750 F. A suitable temperature is 1000 to 1100 F. Air is then forced into the bottom of the furnace, being drawn in through the suction lines 15 and 16 of blower 17 and forced by the latter through the pipe 18 into the furnace below the perforated bottom plate 9. After combustion of the spent fuller s earth has begun, the fire in the bottom of the furnace is drawn or put out and the further burning of the fullers earth is done without extraneous heat.

The blower 17 is operated to maintain a desired pressure of the gas being forced into the fullers earth to support the combustion of the latter, which progresses slowly through the bed of earth. A pressure of 4 to 6 pounds is ordinarily suitable for this purpose.

In order to prevent sintering-of the clay by excessive heat, the blower 17 is caused to draw into its suction line 16, through the pipe 20, an inert gas, such as flue gas from the stack 13. Valves 22 and 23 are provided in the lines 15 and 21, respectively, by which the proportions of air and of flue gas forced into the bed of fullers earth by the blower 17 may be controlled to secure the desired temperature therein. It has been found that a temperature of 1000 to 1200 F. is

'most suitable, and in any event the temperature is so controlled as to prevent sintering of the fullers earth. As is readily appar-. ent, the relative proportions of air and flue gas employed will vary with the precise temperature to be maintained, and with the relative roportions of organic material contained in the clay. The valves 22 and 23 may be readily set to secure the desired re sults. By using an inert gas such as flue gas in conjunction with the oxygen containing gas employed for combustion of the organic matter in the earth, a more rapid burning of the earth may be effected without exceeding the desired control temperature or impalring the decolorizing eficiency of the revivified product.

I claim:

1. The method of revivifying spent fullers earth which comprises initiating local combustion in one part of a bed of spent fullers earth, causing the combustion to pro 'ess therethrough by forcing air into,

the ed of fullers earth at the point where combustion is begun, and admixing with said air an inert gas to control the tempera ture obtained in the combustion of the fullers earth.

2. The method of revivifyingspent fullers earth which comprises initiating local 5 combustion in one part of a body of spent fullers earth, causing the combustion to progress therethrough by forcing air into the body of fullers earth at the point where combustion is begun, removing the combustion gases evolved from thefullers earth and mixing at least part of the combustion gas removed with the air forced into the body of fullers earth.

- ROBERT E. WILSON. 

